Differences of Roman Catholic and Greek Orthodox

What are some of the major differences in beliefs and practices between Roman Catholic and Greek Orthodox? Curious as my daughter is dating someone of this faith and I would like to know myself as to how our faiths differ, especially should this relationship continue to more serious… thanks

The Orthodox is new to me also.

The biggest and most fundamental difference is that the Catholic Church has Peter while the EO churches do not. The main thing we have in common is valid apostolic succession and all of the seven sacraments.

What does “has Peter” mean?

Allow me to try and clarify. The Roman Church recognizes Peter’s primacy among the Apostles of Christ, and that his See (Rome) and his successors (the successors of Peter (the Popes)) have teaching authority over the other Apostles, and their respective Sees and successors.

The Orthodox churches, do not hold the primacy of Peter. They understand that the each bishop (called metropolitan or patriarch) has authority within his own See, with special significance given to the Bishop of Rome and the Patriarch of Constantinople, significance without any real powers of authority. The orthodox also celebrate mass differently, usually with the language of the local community (I.e., Greek Orthodox use Greek, Russian orthodox use Church Slavonic, etc.), as well as varying traditions.

Orthodox Christians also hold a different concept of the nature of God. Catholic teaching is that the Holy Spirit comes from both the Father and the Son (as it is expressed in the Creed); Orthodox hold that the Spirit comes from the Father alone (as is expressed in their creed (which is older than the Creed of the Latin Church). This is the Filioque controversy.

Those are the main dofferences. Orthodox Churches do hold valid Apostolic Succession and valid sacraments.

These are the main differences and probably more than you were looking for, but there it is.


There are substantial differences, but nothing I think you should be overly concerned about. There are more similarities than differences and most of the misunderstanding is due to a different way of saying the same thing, using different wording, or approaching a topic from a different angle while ending at the same destination; though not all.

If you really want to know what the Orthodox Church believes in a brief, easy read, pick up a copy of The Orthodox Church by Timothy Ware (now Metropolitan Kallistos Ware).


The above links should help. The main differences between us Catholics and the Orthodox is that we believe that the Holy Spirit proceeds from the Father and the Son, whereas they believe that He only proceeds from the Father, and that we believe that the Bishop of Rome has all authority over the Church as the Vicar of Christ, and they believe he only is the first among equals.

The reasons that our Churches are separated are virtually all political and historical rather than theological. In the view of the Catholic Church, the Orthodox are our brethren, with valid sacraments and holy orders. Here’s what the Catechism has to say:
838 “The Church knows that she is joined in many ways to the baptized who are honored by the name of Christian, but do not profess the Catholic faith in its entirety or have not preserved unity or communion under the successor of Peter.” Those “who believe in Christ and have been properly baptized are put in a certain, although imperfect, communion with the Catholic Church.” With the Orthodox Churches, this communion is so profound “that it lacks little to attain the fullness that would permit a common celebration of the Lord’s Eucharist.”

That is not true. Both the Catholic and Orthodox Churches believe that the Holy Spirit proceeds from both the Father and the Son. The disagreement rests with whether or not the Catholic Church had the authority to change the Nicene Creed in order to specify this – the Filioque addition.

You sure? I don’t think so… Could you provide some sources?


We believe the Holy Spirit comes from the Father but is sent by the Son. We don’t believe in duel procession.

I am still scratching my head at “the Catholic Church has Peter while the EO churches do not.” :stuck_out_tongue:

The Pope is the successor to Peter. That’s what I meant. I didn’t feel like going into long detailed definitions since the details of things like Papal Primacy can be found in the Catholic Answers articles on this website.

This isn’t accurate. While there are many Orthodox who state the Catholic version of the Creed may actually be more accurate than the Orthodox, the Orthodox Church never acquiesced. The mere fact the Orthodox Church believed the Catholic Church did not utilize the appropriate means to make the change prevented any further discussion on the matter. The Orthodox Church to this day empathically upholds the original Creed. There can be a discussion about which one is more accurate or if both in a sense are accurate, but the Orthodox Church does not support the Filioque in any way and according to the Orthodox Church, it never will unless the appropriate process is conducted and they universally accept it.

I believe it was meant to say the Orthodox Church does not accept the Pope as the universal leader of the earthly Church, Papal Primacy, as the Vicar of Christ.

You didn’t say anything differently than I did.

To infer however as one person did that one Church believes (irrespective of documentation) that the Holy Spirit proceeds from Two Person of God while the other Church believes that the Holy Spirit proceeds from only One Person of God is emphatically wrong. The Orthodox Church does indeed believe what the Filioque states.

As far as whether or not the Filioque adds accuracy to the creed, I didn’t address that.

There is absolutely no difference in the belief. Only a disagreement in how the creed was changed.

No, it does not. You stated:

Both the Catholic and Orthodox Churches believe that the Holy Spirit proceeds from both the Father and the Son.

It is not accurate. Only one believes this, the other does not. One believes the Holy Spirit proceeds only from the Father.

Here is the creed from this Greek Orthodox link: goarch.org/chapel/liturgical_texts/creed

I believe in one God, Father Almighty, Creator of
heaven and earth, and of all things visible and invisible.

And in one Lord Jesus Christ, the only-begotten Son of
God, begotten of the Father before all ages;

Light of Light, true God of true God, begotten,
not created, of one essence with the Father
through Whom all things were made.

Who for us men and for our salvation
came down from heaven and was incarnate
of the Holy Spirit and the Virgin Mary and became man.

He was crucified for us under Pontius Pilate,
and suffered and was buried;

And He rose on the third day,
according to the Scriptures.

He ascended into heaven
and is seated at the right hand of the Father;

And He will come again with glory to judge the living
and dead. His kingdom shall have no end.

And in the Holy Spirit, the Lord, the Creator of life,
Who proceeds from the Father, Who together with the
Father and the Son
is worshipped and glorified, Who
spoke through the prophets.

In one, holy, catholic, and apostolic Church.

I confess one baptism for the forgiveness of sins.

I look for the resurrection of the dead,
and the life of the age to come.


For some individuals (I happen to be one of them), but not the Church as a whole. And depending on how one defines the differences, they can be massive.

You comments are incorrect. The Orthodox Church does not believe that the Holy Spirit proceeds ONLY from God the Father, to the exclusion of God the Son. Cutting and pasting the creed does not change this fact.

There is no difference in belief.

There is a spat over changing the creed.

Ok. The entire Orthodox Church disagrees with you, but I will not argue.

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